Mechanically-activated tools for gripping tubular articles or workpieces, such as tools described in U.S. Pat. No. 7,909,120 (Slack), can require some torque reaction in order to be activated and set. This torque reaction can be provided externally by manual or automated means separate from the primary load path and the workpiece; however, a typical method of reacting this torque is through frictional engagement with the tubular workpiece. Generally, such tools are provided with a land element (or “bumper”) that is designed to engage the exposed face of the tubular (or coupling) and which requires some applied compressive load at this interface to generate the required friction to adequately react the required torque. In many cases the activation torque required varies with setdown load, and will be dependent on how the load is reacted internally, including the diameter and nature of the internal bearing faces, friction generated by rotating seals, and incidental friction resulting from lateral loads applied to the tool.
The variability of the load reaction in some tools results in situations where generating adequate torque reaction is either difficult or impossible to achieve consistently. Such inability to react adequate torque typically occurs when the diameter of the casing (or other tubular item), and consequently the diameter at which the land element is bearing and reacting torque on the casing, is small relative to the internal bearing surfaces of the tool and associated seals. The need to supplement or enhance this torque reaction is apparent in these cases. Some means for increasing this torque are known in the art, including:                1. Reacting the torque load at an angle relative to the applied setdown load (such as, by way of non-limiting example, a conical land element);        2. Adding friction-enhancing features, materials, and/or surface finish to the bearing face on the land element; and        3. Using means such as an internal air spring that will reduce the internally-reacted loads.        
Such means have proved effective for use with some gripping tools, including internally-gripping casing running tools. However, uncertainty as to the ability to generate the required reaction has been increased by the recent development of external-gripping casing running tools having higher capacities and increased internal bearing and seal diameters relative to the casing diameter.
As such, there is a need for a mechanically-activated mechanism that will grip a pipe or coupling such that the gripping force has a mechanical advantage beyond that available with simple land element geometries reacting a generally axially-applied load on the face of the pipe or coupling. This need is especially apparent for pipe and couplings that have a limited ability to react bearing loads and torque on the exposed face, typical to some premium connections with flush or near-flush geometries.